Punka-fan.



J. DfF. ANDREWS.

. PUNKA FAN.

APPLIoATIoN FILED SEPT. z, 1905. RENBWBD SEPT. 23, 1907.

'Patented May 21, 1912.

' WICnesses l liu/@W601i ,Y Joseph D'evonportF-mne Andrews. j@ by M1145@ I His AC {(Orrley. l

JOSEPH DEVONPORT FINNEY ANDREWS, OF LONDON, ENGLAND.

PUNKA-FAN.

Specification of Letters Patent.

Patented May 21, 1912".-

Applieation led September 2, `1905, Serial No. 276,831. Renewed September 23, 1907. Serial No. 394,202.

To all whom fit may concern:

Be it known that I, JosnPi-I DnvoNron'r Funny ANDREWS, a subject of the King of Great Britain and Ireland, residing at 2 Park avenue, East Sheen, London, S. W., England, have invented certain new and useful Improvements in Punka-Fans, of which the following is a specification.

My invention relates to oscillating or punka fans and more especially to electrically driven fans of that type.

The objectof the invention is to provide a highly efficient fan of the character stated, which will be of low cost to manufacture and which will not require greattechnical skill to keep in working condition.

In carrying out my invention I connect an ordinary punka or hand fan directly or indirectly to the pivoted armature of an electro-magnet and connect the switch or controlling means of the exciting circuit of the magnet or magnets to the armature in such manner that the punka or other fan is automatically oscillated and with the desired snap action or flick at the end of each oscillation, but without causing noise or impact of any kind.

One form of my invention is shownl diagrammatically in the accompanying draw ing, in which- Figure l is a front elevation and Fig. 2-

a rear elevation with the electric connections omitted.

In the particular embodiment of the invention shown in the drawing, two electromagnets M and M2 are arranged oppositeeach other with theircommon armature A mounted on a horizontal shaft B located midway between the magnets. The shaft B carries a contact member H for closing the circuit through the exciting coils of the magnets in alternation. The contact member H has an extended lower arm adapted to engage sets of stationary contact studs G and two spaced arms 7L at its upper end which are adapted to be engaged by a pin J carried by the armature A. A spring O is attached to the contact member H at a point P above its axis of oscillation and to a fixed point R vertically beneath the shaft B. The contact studs G of each set are connected in series by resistances K, and the outer end stud of each set is connected to an end L of the exciting coil of one of the magnets. One lead wire N is connected to the axis of the contact member H and the other lead wire L runs direct to the exciting coils of the magnets. y

The fan F is carried by a disk D mounted on the shaft B in frictional engagement with the armature A b y a thumb screw S and has a counter-weight IV to balance the weight of the fan. The ali-mature A also has a counter-weight IN2.

According to the arrangement shown in the drawing, the armature being in one eX- treme position, for instance the right hand, the contact member H in engagement with the left-hand stud G, the current passing from lead wire N to contact member H, to extreme left-hand contact G, through exciting coil wire L of left-hand magnet M2 and back through leady wire L, the magnet M2 will be energized and operate to draw the armature toward the left. The armature moves freely for a short distance into a somewhat stronger field, engages the lefthand arm /i and moves the contact member with it so that the left-hand set of resistances K are gradually thrown into circuit. The armature A is now in strong magnetic field and the opposition of the spring O is reduced to Zero, and accordingly the armature and fan move a short distance at high speed or with a flick. Upon the movement of the spring O past the dead center, it operates to throw the contact member H into the extreme opposite position breaking the circuit through the left-hand magnet M2 and closing it through the right-hand magnet M. This change of circuits takes place before the armature can impinge upon the left-hand magnet, its motion to the left being arrested and the return movement to the right begun under the magnetic action of the right-hand magnet M.

I do not desire to limit myself to the particular construction and arrangement of parts here shown, but aim in the appended claims to cover all modifications which are within the scope of my invention.

What I claim as new and desire to secure by Letters Patent in the United States is t- 1. The combination of a fan, a pivoted armature to which said fan is attached, oppositely acting electromagnets for oscillating said armature, a pivoted switch member, contacts in the circuits of the electromagnets controlled by said switch member, a lost-motion connection between the armature and the switch member, and a biasing spring for reinforcing the movement of the switch member in either direct-ion.

2. The combination of a fan, a pivoted armature to which said fan is attached, an electromagnet for oscillating said armature, and means for balancing said armature and fan.

3. The combination of a pivoted armature, means for balancing the armature, an electromagnet for oscillating the armature, a fan pivotally carried by the armature, means for adjusting the position of the fan Copies of this patent may be obtained for angularly relatively thereto, and means for balancing the fan.

4. The combination of a fan, an armature to which said fan is attached, an electromagnet for oscillating the fan, a switch member actuated by the armature, contacts in the circuit of the electromagnet controlled by the switch member, and resistance interposed between the contacts.

In witness whereof I have hereunto set my hand this 23rd day of August 1905.

JOSEPH DEVONPORT FINNEY ANDREWS.

Vitnesses FRED. L. RAND, F. J. SKoYLEs.

five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

